Hitherto, a nonflammable “HFC refrigerant” such as R410A is used as refrigerant for refrigeration cycle apparatus. Unlike a related-art “HCFC refrigerant” such as R22, R410A has an ozone depletion potential (hereinafter referred to as “ODP”) of zero and hence does not deplete an ozone layer. However, R410A has a property of high global warming potential (hereinafter referred to as “GWP”).
Thus, as a part of prevention of global warming, consideration has been made to replace the HFC refrigerant having high GWP, such as R410A, with refrigerant having low GWR
As a candidate for such refrigerant having low GWP, there is given a HC refrigerant such as R290 (C3H8; propane) and R1270 (C3H6; propylene), which are natural refrigerants. However, unlike nonflammable R410A, the HC refrigerant has flammability at a strongly flammable level, and hence caution is required for refrigerant leakage.
Further, as another candidate for the refrigerant having low GWP, there is given a HFC refrigerant having no carbon-carbon double bond in a composition thereof, such as R32 (CH2F2; difluoromethane) having GWP lower than R410A.
Further as a similar refrigerant candidate, there is given a halogenated hydrocarbon having a carbon-carbon double bond in a composition thereof, which is a kind of the HFC refrigerant similarly to R32. As such a halogenated hydrocarbon, there are given, for example, HFO-1234yf (CF3CF═CH2; tetrafluoropropene) and HFO-1234ze (CF3—CH═CHF). Note that, to distinguish the HFC refrigerant having a carbon-carbon double bond in a composition thereof from the HFC refrigerant having no carbon-carbon double bond in a composition thereof, such as R32, the HFC refrigerant having a carbon-carbon double bond in a composition thereof is expressed as “HFO” through use of “O” of an olefin (unsaturated hydrocarbon having a carbon-carbon double bond is called an olefin) in most cases.
The above-mentioned HFC refrigerant (including the HFO refrigerant) having low GWP is not as strongly flammable as the HC refrigerant such as R290 (C3H8; propane), which is a natural refrigerant, but the HFC refrigerant (including the HFO refrigerant) having low GWP has flammability at a slightly flammable level unlike nonflammable R410A. Consequently, similarly to R290, caution is required for refrigerant leakage. Refrigerant having flammability is hereinafter referred to as “flammable refrigerant” even when the flammability is at a slightly flammable level.
When those kinds of flammable refrigerant are used, it is necessary to secure safety from possible refrigerant leakage not only during the use of the refrigeration cycle apparatus (during the operation of the refrigeration cycle apparatus) but also during the steps of manufacturing, shipping, storing, and transporting the refrigeration cycle apparatus. There are proposed a great variety of technologies for securing the safety during the use of the refrigeration cycle apparatus (during the operation of the refrigeration cycle apparatus). On the other hand, there are only a few proposals for technologies that may be applied to the steps of manufacturing, shipping, storing, and transporting the refrigeration cycle apparatus. Under those circumstances, there is disclosed a refrigerating and air-conditioning apparatus to be shipped under a state in which nonflammable refrigerant is newly sealed (see, for example, Patent Literature 1).